2011-226B.1 - Laserfiche WebLink

Home Browse Search

rusting or contamination occurs after the completion of the surface preparation, prepare the ` Vve surfaces again to the initial requirements . Perform surface preparation work only when the temperature of the steel surface is at least 5 °F above the dew point temperature . 560-7 . 2 Mechanical Removal of Surface Defects : Break all corners resulting from sawing, burning, or shearing. In areas where burning has been used, remove the flame hardened s surface of the steel to the extent necessary to achieve the required surface profile after abrasive blast cleaning. Remove all weld slag and weld spatter. Conduct all of this work in accordance with AASHTO/NSBA Steel Bridge Collaboration S 8 . 1 . 560-7 .3 Cleaning : Clean all steel surfaces in accordance with the requirements of SSPC- SP 1 . 560-7 .4 Washing : Wash all steel surfaces in accordance with the requirements of SSPC - SP 12 . 5604 .5 Soluble Salts Detection and Removal : Determine the chloride, sulfate and nitrate concentrations on all steel surfaces using soluble salts test kits meeting the requirements of 560-2 . 4 . Measure the concentration levels using the method described in SSPC -TU 4 . Perform the tests after washing and after each applied coat of the coating system . Test three random locations in the first 1000 square feet and one random location for each subsequent 1000 square feet. Ensure the non-visible surface contaminant concentrations on blast-cleaned surfaces do not exceed the levels in SSPC - SP 12 Table Al NV12 for chloride , soluble ferrous iron and sulfate and 10 µg/cmZ for nitrate . When any concentration exceeds these levels rewash the entire surface area and retest. If additional washing does not reduce the concentration to the acceptable level, a surface treatment or water additive may be used . Use a surface treatment or water additive that is approved by the coating system supplier and the Engineer. 560-7 .6 Abrasive Blast Cleaning : Prepare steel by abrasive blast cleaning to "Near- White" metal condition as defined in SSPC - SP 10 . Use SSPC VIS 1 as an aid in establishing cleanliness . After abrasive blast cleaning, ensure the surface profile meets the requirements of the coating manufacturer ' s product data sheet. Determine the surface profile using replica tape in accordance with ASTM D 4417 , Method C . Perform all abrasive blast cleaning within a containment system to ensure confinement of all particulates . Design the containment system to comply with all applicable Federal , State, and Local regulations . Ensure the abrasive blast cleaning does not produce holes , cause distortion , remove metal, or cause thinning of the substrate . 560-7. 7 Hand and Power Tool Cleaning : Prepare steel by power and hand tool cleaning as defined in SSPC- SP 11 , SSPC- SP 3 , and SSPC- SP 2 for touch up and repair when approved by the Engineer. Use SSPC -VIS 3 as an aid in establishing cleanliness . 560-8 Surfaces Not to be Coated . 560-8 . 1 Galvanized Surfaces : Do not coat galvanized surfaces unless specified in the Contract Documents . 560-8 . 2 Surfaces to be in contact with Concrete : Do not coat the areas of contact surfaces of steel to be encased or embedded in concrete , or coated with concfete unless specified in the Contract Documents . When specified, prepare the contact surfaces and apply primer . 560-8 .3 Faying Surfaces : After application of the primer, protect the contact surfaces of members to be joined by high- strength bolts in friction type joints from all other coatings and foreign material . - 163 - FPID ( S ) : 423186 - 1 - 5 8 -01 - E �k